1. Field of the Invention
The present invention relates to a safety switch device for use in the manufacture of large, round cylindrical vessels. More specifically, the device is provided with interconnected switches which are positioned adjacent to a cylindrical vessel located on turning rolls such that if the vessel raises off one of the turning rolls, at least one of the switches will sense the movement of the vessel and will automatically deactivate the turning rolls, thus preventing the vessel from coming off the turning rolls and simultaneously activate a warning device.
2. Description of the Related Art
Construction of large cylindrical vessels is frequently accomplished with the vessel resting on turning rolls so that the cylindrical axis of the vessel lies in a horizontal position and the vessel is cradled on the roll tires of the turning rolls. The turning rolls are provided with motor means for rotating the roll tires and thereby rotating the vessel which rests thereon. Usually the motor means is an electric roll driving motor which attaches to and powers the rotation of the roll tires. The electrical roll driving motor is activated in order to rotate the vessel. When the electric roll driving motor is activated, the vessel rotates on the roll tires in a direction counter to the movement of the roll tires. For example, if the roll tires are rotating in a clockwise direction, the vessel will rotate in a counterclockwise direction.
The vessel will generally continue to rotate on the turning rolls until the roll tires encounter a non-uniform feature. Upon encountering a non-uniform feature, one or both ends of the vessel may move upward, driven by the propelling force of the motor driven turning rolls, resulting in a situation where the vessel can easily jump, roll or fall off the turning rolls and injure or destroy lives and equipment.
One object of the present invention is to provide a warning, either visual or audible or both, whenever the vessel rises off one of the turning rolls. Another object of the invention is to automatically discontinue power to the motor means which drives the turning rolls whenever the vessel rises off one of the turning rolls. Still a further object of the invention is to provide a relatively inexpensive safety device which can be used with existing turning rolls with little or no modification to existing equipment.